as a PDF
Transcript
as a PDF
Ital. J. Agron., 7, 1, 57-63 Italian Durum Wheat Agroclimatic Areas: their Influence on Kernel Shape and Semolina Yield P. NOVARO, F. COLUCCI, and M.G. D’EGIDIO Istituto Sperimentale per la Cerealicoltura, Roma, Italy Corresponding author: P. Novaro, Sezione di Pianificazione degli Esperimenti, Istituto Sperimentale per la Cerealicoltura, via Cassia 176, 00191 Rome, Italy. Tel: +39 06 3295705; Fax: +39 06 36298457; E-mail: [email protected] Received: 2 August 2002. Accepted: 28 May 2003. ABSTRACT BACKGROUND. Previous research on durum wheat established the relationships between kernel shape and semolina yield and classified durum wheat growing areas as agroclimatic areas. The aim of this work was to check whether kernel shape and semolina yield were modified when durum wheat varieties were grown in different agroclimatic areas. METHODS. Grain samples (n = 240) were analysed of 15 durum wheat varieties grown in trials conducted by the Rome Experimental Institute for Cereal Research during 1998 and 1999; trial locations were grouped in 8 agroclimatic areas. For each sample different measurements for describing kernel shape were determined by image analysis procedures, plus 1,000-seed weight and semolina yield. Factorial analysis of variance allowed the effects of growing area, genotype and their interactions to be calculated for the considered characteristics. RESULTS. Factorial analysis of variance shows factors and interactions significant for all the characteristics. The significance of the interactions does not allow tests of the main effects to be performed. For the “year × growing area” interaction the 1999 results are always significantly lower than those of 1998, however North-Central Adriatic Coast appears to be the best environment in both years. For the “growing area × genotype” interaction, considering kernel volume, Simeto appears to be the best variety in all the environments, followed by Creso; Mongibello performs well, especially in Sicily where this variety was selected. For 1,000-seed weight Simeto, Creso and Colosseo confirm their good results in all areas. For semolina yield San Carlo achieves the best values. CONCLUSIONS. The North-central Adriatic Coast results as being the best growing area for both kernel shape and semolina yield, followed by the Apennines. Typical durum wheat growing areas (Apulia, Sicily and Sardinia) show different results over the years due to very variable weather conditions. Considering the “growing area × genotype” interaction, Simeto appears to be the best variety in all growing areas for kernel volume and 1,000-seed weight; San Carlo gives the best values of semolina yield. The most favourable growing areas for the considered characteristics are those with stable climatic conditions over the years. Key-words: durum wheat, agroclimatic areas, image analysis, kernel shape, semolina yield. INTRODUCTION Studies on the differences among wheat varieties grown in several agroclimatic areas in terms of kernel size and shape and semolina yield are an active area of research. Kernel size and shape are evaluated by image analysis techniques to obtain objective measurements while preserving intact seed for sowing. Image analysis systems have been developed on a variety of applications in agriculture. Many researchers studied cereal products to describe the textural appearance of bread crumb (Bertrand et al., 1992; Sapirstein et al., 1994; Zayas, 1993; Zghal et al., 1999); Symons et al. (1996) developed an objective instrumental method for counting specks in semolina, whereas Bacci et al. (1995) studied an automatic system for the evaluation of durum wheat grain alterations such as yellow-berry and shrivelling. Image analysis techniques have also been applied to both kernel classification and discrimination (Zayas et al., 1985; 1986; 1994; Sapirstein et al., 1987; Thomson and Pomeranz, 1991; Zayas and Steele, 1996; Sapirstein and Kohler, 1999) and to differentiate wheat-grain samples according to grain morphology or other attributes related to milling quality (Marshall et al., 58 Novaro et al. 1986; Zayas et al., 1986; Symons and Fulcher, 1988 a, b; Draper and Keefe, 1989; Newman et al., 1989; Sapirstein, 1995 ; Wrigley and Morris, 1995; Troccoli and Di Fonzo, 1999). Berman et al. (1996) applied image analysis to whole-grain samples to predict milling quality. In selecting for this character in bread wheat, they found four parameters (area, length of minor and major axes and kernel volume) and test weight to be related to flour yield. Novaro et al. (2001) studied the relationships among kernel shape and size measurements obtained by image analysis, 1,000-seed weight, test weight and semolina yield to define equations useful for predicting semolina yield in durum wheat: they found kernel volume jointly with 1,000-seed weight or test weight to be the best predictors. On the basis of these results and having classified durum wheat growing areas as agroclimatic areas by using the results of variety testing trials conducted by the Rome Experimental Institute for Cereal Research from 1975 to 2001, the present work was done to determine the influence of growing areas on kernel shape and size and semolina yield and how these characteristics are modified among varieties and for a single variety when grown in different agroclimatic areas. MATERIALS AND METHODS Samples Grain samples of 15 durum wheat varieties included in a national network of trials conducted in Italy during 1997-98 and 1998-99 growing seasons were analysed. The varieties, representative of genotypes currently grown in Italy, were cultivated in 48 locations in the first season and 46 during the second. Due to the en- vironmental diversity of Italy and on the basis of the results of trials on durum wheat conducted by the Rome Experimental Institute for Cereal Research during the last 30 years, the trial locations were grouped in 8 different agroclimatic areas (Novaro, 1997): Po Valley, North-Central Adriatic Coast, North-Central Tyrrhenian Coast, North-Central Apennines, Central-South Apennines, Adriatic Ionian Coast, Sicily and Sardinia (Table 1). Composite samples for each variety were made up by mixing grains from locations belonging to the same agroclimatic area (Lukow and McVetty, 1991; Mariani et al., 1995). For kernel characteristics 240 samples were analysed as duplicate sets (n=480), for 1,000-seed weight and semolina yield, 240 samples were considered because replicates were not available. Image analysis A specific macro, a succession of image analysis procedures, was developed on an image analysis system which included a videocamera (JVC TK-C 1380), a 5000 K light and KS 400 software (ZEISS). The system was used to study the durum wheat kernel shape and dimensions. Images were captured for each sample as duplicate sets of 50 grains randomly chosen and arranged to minimise contact among the grains (Berman et al., 1996). For each sample different measurements useful for describing kernel shape such as area (AREA), perimeter (PERIM), length of minor (AMIN) and major (AMAX) axes and volume (VOL) were taken. According to Berman et al. (1996), on the assumption that a grain is an ellipsoid with circular cross section, the kernel volume was computed applying the formula: π·AMAX·AMIN2/6. Technological tests Semolina yield (SEM) and 1,000-seed weight (SEEDW) were considered: 1,000-seed weight Table 1. Italian durum wheat growing areas. 1 2 3 4 5 6 7 8 Agroclimatic areas Geographical areas Po Valley North-Central Adriatic Coast North-Central Tyrrhenian Coast North-Central Apennines Central – South Apennines Adriatic – Ionian Coast Sicily Sardinia Lombardy, Veneto, Emilia Romagna, Marche, Abruzzo (Coast) Tuscany (Coast), Latium (Coast) Tuscany (Apennines), Umbria, Latium (Apennines) Campania (Apennines), Molise, Basilicata (Apennines), Calabria Apulia, Basilicata (Coast) Sicily Sardinia Durum Wheat Agroclimatic Areas 59 Table 2. Mean value and standard deviation of characteristics considered. Variables Code Kernel minor axis length (mm) Kernel major axis length (mm) Kernel perimeter (mm) Kernel area (mm2) Kernel volume (mm3) 1,000-seed weight (g) Semolina yield (%) AMIN AMAX PERIM AREA VOL SEEDW SEM was determined as the mean of 2 samples of 15 g each, semolina was obtained from a sample of 3.5 kg by laboratory scale milling on a Buhler MLU 202 test mill with three breaking and three sizing passages. The milling equipment (mill and purifier) was adjusted to obtain semolina within 0.9% ash content, according to the Italian law. The semolina yield (%) was estimated as the ratio between milling product (semolina) and raw material (grain). Statistical analysis Factorial analysis of variance was computed for kernel characteristics, semolina yield and 1,000seed weight using the SPSS software package (Norusis, 1996); year, growing area and variety were considered as fixed factors. For semolina yield and 1,000-seed weight, the “year × growing area × genotype” interaction was used as error variance because replicates were not available. Duncan’s multiple range test was applied to reveal significant differences among the means for factors and interactions. RESULTS AND DISCUSSION Mean and standard deviation of all the measured characteristics are reported in Table 2; the Measures (n) Mean value Standard Deviation 480 480 480 480 480 240 240 3.3 7.5 18.4 18.1 42.8 43.3 66.0 0.2 0.3 0.8 1.8 6.6 5.1 4.2 variability values for 1,000-seed weight, semolina yield and kernel measurements are those usually found for durum wheat in Italy, as reported by Novaro et al. (2001). Factorial analysis of variance (Table 3) shows factors and interactions significant for all the characteristics with the exception of the “year × genotype” interaction relative to semolina yield. Having found significant interactions, tests of the main effects are not performed unless for the factor “growing area”, which is important for us because it is a new way of considering trial locations. The mean values for each growing area, tested by Duncan’s multiple range test, are reported in Table 4 for all characteristics. The best growing area both for kernel shape measurements and for 1,000-seed weight and semolina yield results as being the North-Central Adriatic Coast and in decreasing order, North-Central and Central-South Apennines. Adriatic-Ionic Coast, Sicily and Sardinia, typical durum wheat growing areas, are placed at a lower level probably as a consequence of high climatic variability over the years (Desiderio et al., 1998; 1999). In a previous work, Novaro et al. (2001) studied the relationships among kernel size and shape measurements, 1,000-seed weight and semolina yield and found kernel volume jointly Table 3. Factorial analysis of variance for the characteristics considered. Source of variation Year (Y) Growing area (GA) Genotype (G) Y × GA Y×G GA × G Y × GA × G Error AREA 695.6 19.2 26.0 13.1 1.8 1.2 0.9 0.5 ** ** ** ** ** ** ** ** PERIM 91.6 2.0 8.6 1.7 0.3 0.2 0.1 0.1 ** ** ** ** ** ** ** ** °P≤ 0.10; *P≤ 0.05; **P ≤ 0.01; ns= not significant AMIN 9.15 0.52 0.26 0.23 0.03 0.02 0.02 0.01 ** ** ** ** ** ** ** ** AMAX VOL 8.61 ** 0.19 ** 1.86 ** 0.17 ** 0.04 ** 0.03 ** 0.02 ** 0.01 * 8409.5 377.2 262.2 173.9 22.8 16.5 12.4 7.1 SEEDW ** ** ** ** ** ** ** ** 1339.9 196.5 80.3 27.7 8.7 2.3 1.4 – ** ** ** ** ** ** ** SEM 1379.0 ** 119.8 ** 10.0 * 73.9 ** 5.6 ns 6.9 ° 5.3 ** – 60 Novaro et al. Table 4. Comparison among growing areas for the characteristics considered. Growing areas Po Valley North-Central Adriatic Coast North-Central Tyrrhenian Coast North-Central Apennines Central – South Apennines Adriatic – Ionian Coast Sicily Sardinia Mean (1) PERIM (mm) AREA (mm2) ce (1) a bc b bd b de e 17.8 19.3 18.0 18.1 17.9 18.1 17.7 17.5 18.1 18.2 18.8 18.2 18.3 18.3 18.4 18.3 18.2 18.4 AMIN (mm) cd a d cd cd b bc cd 3.23 3.45 3.26 3.29 3.25 3.22 3.17 3.15 3.25 AMAX (mm) cd a c b cd d e e 7.5 7.6 7.4 7.5 7.5 7.6 7.5 7.5 7.5 d a e d d ab bc d VOL (mm3) 41.8 48.4 42.5 43.6 42.5 42.2 41.0 40.2 42.8 cd a c b c c de e SEEDW (g) 42.1 47.1 43.3 44.8 45.9 43.3 37.2 42.6 43.3 f a d c b d g e SEM (%) 65.5 69.1 63.8 66.7 66.4 63.6 64.6 68.2 66.0 d a f c c f e b Duncan’s multiple range test, P= 0.05 Table 5. Kernel volume, 1,000-seed weight, semolina yield: year × growing area interaction. Growing areas 1998 Po Valley North-Central Adriatic Coast North-Central Tyrrhenian Coast North-Central Apennines Central – South Apennines Adriatic – Ionian Coast Sicily Sardinia Mean (1) 43.1 50.7 47.4 49.9 45.9 47.6 45.7 45.2 47.0 VOL (mm3) 1999 e (1) a bc a d b d d 40.5 46.2 37.6 37.2 39.2 36.8 36.2 35.1 38.6 1998 f cd g g f g gh h 44.2 48.6 46.9 47. 48.0 47.4 39.4 46.6 46.1 SEEDW (g) 1999 g a d c b c kl e 40.1 45.7 39.6 42.2 43.8 39.2 35.0 38.5 40.5 1998 j f k i h l n m 66.3 72.3 65.1 68.0 68.5 69.4 66.8 70.5 68.4 SEM (%) 1999 f a gh d d c e b 64.7 65.9 62.5 65.3 64.2 57.8 62.3 65.9 63.6 hi f j g i k j f Duncan’s multiple range test, P= 0.05 with 1,000-seed weight to be useful traits for predicting semolina yield. On the basis of these results only kernel volume, 1,000-seed weight and semolina yield will be discussed. For the “year × growing area” interaction relative to the three characteristics chosen it can be noted that the 1999 results are always signifi- cantly lower than those of 1998, in any case the North-Central Adriatic Coast appears to be the best environment, followed by North-Central and Central-South Apennines; the Adriatic-Ionic Coast shows good results during 1998 for the favourable weather conditions during the year, whereas in 1999 it assumes a lower level fol- Table 6. Kernel volume (mm3): growing area × genotype interaction. Genotypes 8 CRESO* DUILIO* SIMETO* COLOSSEO GARGANO GIANNI MONGIBELLO NEFER OFANTO PARSIFAL SAN CARLO VARANO Mean 45.3 42.3 46.7 41.5 40.7 40.9 44.2 36.7 39.3 40.5 41.9 39.4 40.2 7 ab bd a bd ce ce ac e de ce bd de (1) 44.2 40.7 46.0 42.8 43.1 38.4 44.9 39.1 43.7 35.9 41.5 44.6 41.0 Growing areas 6 1 ab bd a ac ac de ab ce ab e bd ab 44.6 45.5 44.8 41.8 41.8 41.7 41.6 40.4 42.6 41.3 42.6 43.5 41.8 ab a ab ab ab ab ab b ab ab ab ab 45.8 45.1 43.9 45.7 45.1 40.3 43.9 38.0 44.1 42.3 41.4 42.9 42.2 a a ab a a bc ab c ab ab ac ab 3 45.3 44.4 50.2 45.1 43.2 43.1 39.2 44.3 43.5 43.9 37.7 43.4 42.5 5 b b a b b b c b b b c b *= control genotypes; the best 3 genotypes in each growing area are reported in bold. (1) Duncan’s multiple range test, P= 0.05 40.4 40.5 46.7 44.5 41.7 39.3 46.5 44.1 43.7 41.8 46.0 46.8 42.5 4 cd cd a ac cd d a ac ac bd ab a 43.7 47.1 50.8 42.8 42.8 44.7 44.1 42.8 46.8 45.5 43.4 44.2 43.6 2 b ab a b b b b b b b b b 48.5 51.4 55.7 51.1 49.9 48.5 52.3 46.6 50.4 47.1 46.4 51.0 48.4 bd bc a bc bd bd ab d bd cd d bc Durum Wheat Agroclimatic Areas 61 Table 7. 1,000-seed weight (g): growing area × genotype interaction. Genotypes 7 CRESO* DUILIO* SIMETO* COLOSSEO GARGANO GIANNI MONGIBELLO NEFER OFANTO PARSIFAL SAN CARLO VARANO Mean 39.6 39.0 40.1 40.3 39.7 36.4 40.1 33.5 36.9 35.7 37.7 39.3 37.2 1 ac c ab a ac ef ab g e f d bc (1) 42.3 45.8 45.2 43.8 43.2 43.9 41.2 40.2 40.9 44.7 44.4 41.9 42.1 Growing areas 3 8 f a ab de e de gh i hi bc cd f 46.5 45.0 46.7 46.2 44.4 43.4 42.1 37.4 41.7 42.6 43.9 41.7 42.6 ab ac a ab ad bd cd e d cd ad d 46.2 45.5 47.1 46.4 42.2 44.4 40.8 43.7 42.6 44.7 42.5 43.1 43.3 bc c a ab h de i ef gh d gh fg 6 46.6 44.8 46.5 47.3 45.3 43.5 44.3 41.4 43.3 41.6 44.8 43.8 43.3 4 ab cd b a c ef de g f g cd ef 46.3 47.0 40.3 45.8 45.8 45.5 44.3 42.1 44.2 45.7 47.8 44.3 44.8 5 bc b g cd cd d e f e cd a e 49.2 47.8 48.5 49.8 46.0 46.1 47.2 45.0 46.5 44.6 48.4 45.8 45.9 2 ab cd bc a f f de g ef g bc f 47.2 49.1 52.4 51.0 48.6 49.9 46.5 43.5 48.5 47.3 48.9 47.7 47.1 e cd a b d c f g d e d e *= control genotypes; the best 3 genotypes in each growing area are reported in bold. (1) Duncan’s multiple range test, P= 0.05 lowed by Sicily (Table 5). These results are in agreement with those reported for the main effects of growing area in Table 4. For the “growing area × genotype” interaction, considering kernel volume (Table 6), Simeto appears to be the best variety in all the growing areas, followed by Creso that decreases in Central-South Apennines. Mongibello has a good performance in the best growing areas, in Sardinia and Sicily where this variety was selected. Duilio gives good results in North-Central Apennines and North-Central Adriatic Coast, as well as in the Po Valley and Adriatic-Ionian Coast. Colosseo stands out particularly in the Adriatic-Ionian Coast, North-Central Tyrrenian Coast and North-Central Adriatic Coast. Finally Varano can be cited for its good performance in the enviroments of Central-South Apennines and Sicily, and Ofanto in North-Central Apennines. Considering 1,000-seed weight, Simeto, Colosseo and Creso, followed by Duilio, have the best values in all areas (Table 7); San Carlo instead gives good results in the Apennines. Considering semolina yield, San Carlo followed by Gianni, Creso and Mongibello give the best values in the best growing areas: North-Central Adriatic Coast and Apennines (Table 8). Colosseo and Nefer give good results in many enviroments except in North-Central Adriatic Table 8. Semolina yield (%): growing area × genotype interaction. Genotypes Growing areas 6 CRESO* DUILIO* SIMETO* COLOSSEO GARGANO GIANNI MONGIBELLO NEFER OFANTO PARSIFAL SAN CARLO VARANO Mean 63.6 59.2 60.7 68.3 62.9 61.9 62.9 64.7 65.6 63.0 65.9 64.4 63.6 3 cd (1) g f a de ef de bc b de b bd 63.1 62.9 66.4 64.2 61.4 64.8 63.2 65.2 61.3 65.2 61.3 62.3 63.8 7 cd ce a bc e b cd ab e ab e de 60.4 65.6 64.7 66.5 64.4 62.6 64.9 68.1 65.8 65.7 66.0 65.0 64.6 1 e bc c b c d bc a bc bc bc bc 65.3 66.4 66.5 67.2 68.5 67.0 65.4 66.1 60.1 66.8 67.7 65.5 65.5 5 d bd bd ab a ac cd bd e bd ab cd 67.0 66.1 64.7 66.3 64.4 69.8 67.1 67.3 66.3 65.8 67.3 66.4 66.4 4 b bc cd bc d a b b bc bd b b *= control genotype; the best 3 genotypes in each growing area are reported in bold. (1) Duncan’s multiple range test, P= 0.05 66.7 64.7 66.9 67.2 67.6 68.0 65.3 65.5 66.2 67.4 71.3 66.3 66.7 8 bd e bd bc bc b de de ce bc a bd 71.0 66.3 67.5 67.4 68.7 66.5 67.7 69.4 70.0 67.8 73.6 68.2 68.2 2 b f ef ef ce f ef cd bc ef a de 68.2 68.2 67.4 67.7 69.2 69.4 71.9 72.2 69.7 69.5 68.5 67.7 69.1 bd bd d cd bc b a a b b bd cd 62 Novaro et al. Coast and North-Central Apennines, respectively. For 1,000-seed weight and semolina yield the second-order interaction was used as error variance to test the first-order interaction; for this reason we have chosen to omit the discussion on the second-order interaction relative to kernel volume. Finally, Central-Adriatic Coast and Apennines, having good water availability during grain filling, result as being the best growing areas for kernel size and shape and semolina yield, but it can be noted that these favourable weather conditions can also encourage the development of fungal diseases. South of Italy instead, a typical durum wheat growing area with high climatic variability, gives different results over the years for the considered characteristics; notwithstanding the fact that this environment is characterised by high temperatures and low soil moisture, it gives advantages such as seed soundness, low yellow-berry and colour improvement (Novaro et al. 1997). CONCLUSIONS Durum wheat growing areas in Italy are quite different in terms of climatic conditions; weather, specially rainfall, is more stable over the years in North and Central Italy than in the South. So, for the considered characteristics, North-Central Adriatic Coast followed by North-Central Apennines result as the best growing areas for all genotypes, whereas typical durum wheat growing areas, Apulia, Sicily and Sardinia, with pronounced climatic variability, give different results over the years. The influence of growing area on genotype behaviour can be summarised as follows: − for kernel volume: Simeto, Creso, Duilio, Colosseo, Mongibello and Ofanto give the best results in all the growing areas, whereas Varano appears to be good in South Apennines and Sicily; − for 1,000-seed weight: Simeto, Colosseo and Creso followed by Duilio have good results in all areas, San Carlo gives good values in the Apennines; − for semolina yield: San Carlo, Gianni, Creso and Mongibello give the best values in the best growing areas. REFERENCES Bacci L., Rapi B., Novaro P., 1995. Application of image processing to the estimation of durum wheat seeds imperfections. Fragmenta Agronomica, 2(46), 118-119. Berman M., Bason M.L., Ellison F., Peden G., Wrigley C.W., 1996. Image analysis of whole grains to screen for flour-milling yield in wheat breeding. Cereal Chem., 73, 323-327. Bertrand D., Le Guerneve C., Marion D., Devaux M.F., Robert P., 1992. Description of the textural appearance of bread crumb by video image analysis. Cereal Chem., 69, 257-261. Desiderio E., Belocchi A., Cecchi V., Fornara M., 1998. Risultati della sperimentazione condotta nel 1997-98. L’Informatore Agrario, 36, 5-20. Desiderio E., Belocchi A., Cecchi V., Fornara M., Mazzon V., 1999. Risultati della sperimentazione condotta nel 1998-99. L’Informatore Agrario, 36, 7-21. Draper S., Keefe P.D., 1989. Machine vision for the characterization and identification of cereals. Plant Varieties Seeds, 2, 53-62. Lukow O.M., McVetty P.B.E., 1991. Effect of cultivar and environment on quality characteristics of spring wheat. Cereal Chem., 68, 597-601. Mariani B.M., D’Egidio M.G., Novaro P., 1995. Durum wheat quality evaluation: influence of genotype and environment. Cereal Chem., 72, 194-197. Marshall D.R., Mares D.J., Moss H.J., Ellison F.W., 1986. Effects of grain shape and size on milling yields in wheat. II. Experimental studies. Austr. J. Agric. Res., 37, 331-342. Newman M.R., Sapirstein H.D., Shwedyk E., Bushuk W., 1989. Wheat grain colour analysis by digital image processing. II. Wheat class discrimination. J. Cereal Sci., 10, 183-188. Novaro P., 1997. Valore di un frumento duro: quali le condizioni per stabilirlo. L’Informatore Agrario, 36, 51-54. Novaro P., D’Egidio M.G., Bacci L., Mariani B.M., 1997. Genotype and environment: their effect on some durum wheat quality characteristics. J. Genet. Breed., 51, 247-252. Novaro P., Colucci F., Venora G., D’Egidio M.G., 2001. Image analysis of whole grains: a noninvasive method to predict semolina yield in durum wheat. Cereal Chem., 78, 217-221. Norusis M.J., 1996. SPSS v.7. SPSS Inc., Chicago, Illinois, USA. Sapirstein H.D., 1995. Variety identification by digital image analysis. In: Wrigley C.W. (ed.): Identification of food-grain varieties, 91-130. Am. Assoc. Cereal Chem., St. Paul, Minnesota, USA. Sapirstein H.D., Kohler J.M., 1999. Effects of sampling and wheat grade on precision and accuracy of kernel features determined by digital image analysis. Cereal Chem., 76, 110-115. Sapirstein H.D., Neuman M.R., Wright E.H., Shwedyk Durum Wheat Agroclimatic Areas E., Bushuk W., 1987. An instrumental system for cereal grain classification using digital image analysis. J. Cereal Sci., 6, 3-14. Sapirstein H.D., Roller R., Bushuk W., 1994. Instrumental measurement of bread crumb grain by digital image analysis. Cereal Chem., 71, 383-391. Symons S.J., Fulcher R.G., 1988a. Determination of wheat kernel morphological variation by digital analysis. I. Variation in eastern Canadian milling quality wheat. J. Cereal Sci., 8, 211-218. Symons S.J., Fulcher R.G., 1988b. Determination of wheat kernel morphological variation by digital analysis. II. Variation in cultivars of soft white winter wheat. J. Cereal Sci., 8, 219-229. Symons S.J., Dexter J.E., Matsuo R.R., Marchylo B.A., 1996. Semolina speck counting using an automated imaging system. Cereal Chem., 73, 561-566. 63 Wrigley C.W., Morris C.F., 1995. Breeding cereals for quality improvement. In: Henry R.J., Kettlewell P.S. (eds.): Cereal Grain Quality. Chapman and Hall, London. Zayas I.Y., 1993. Digital image texture analysis for bread crumb grain evaluation. Cereal Food World, 38, 760-766. Zayas I.Y., Steele J.L., 1996. Image texture analysis for discrimination of mill fractions of hard and soft wheat. Cereal Chem., 73, 136-142. Zayas I.Y., Pomeranz Y., Lai F.S., 1985. Discrimination between Arthur and Arkan wheats by image analysis. Cereal Chem., 62, 478-480. Zayas I.Y., Lai F.S., Pomeranz Y., 1986. Discrimination between wheat classes and varieties by image analysis. Cereal Chem., 63, 52-56. Thomson W.H., Pomeranz Y., 1991. Classification of wheat kernels using three-dimensional image analysis. Cereal Chem., 68, 357-361. Zayas I.Y., Bechtel D. B., Wilson J.D., Dempster R.E., 1994. Distinguishing selected hard and soft red winter wheats by image analysis of starch granules. Cereal Chem., 71, 82 -86. Troccoli A., Di Fonzo N., 1999. Relationship between kernel size features and test weight in Triticum durum. Cereal Chem., 76, 45-49. Zghal M.C., Scanlon M.G., Sapirstein H.D., 1999. Prediction of bread crumb density by digital image analysis. Cereal Chem., 76, 734-742. L’INFLUENZA DEGLI AREALI AGROCLIMATICI SULLA GRANDEZZA E LA FORMA DEL GRANELLO E SULLA PRODUZIONE DI SEMOLA DEL FRUMENTO DURO SCOPO. Avendo classificato in precedenti ricerche le zone di coltura del frumento duro come areali agroclimatici, obiettivo di questo lavoro è controllare se la forma e le dimensioni del granello e la produzione di semola siano influenzati dall’areale di coltivazione e come queste caratteristiche varino tra le varietà e entro una stessa varietà. METODI. Sono stati analizzati 240 campioni di granella di 15 varietà di frumento duro allevate nella rete di prove di confronto varietale coordinata dall’Istituto Sperimentale per la Cerealicoltura di Roma negli anni 1998 e 1999; le località di prova sono state raggruppate in 8 areali. Le misure di forma del seme, ottenute attraverso la metodologia di analisi d’immagine, sono state analizzate insieme al peso 1000 semi e alla resa in semola. Un’analisi fattoriale della varianza ha consentito di evidenziare gli effetti dell’areale di coltivazione sulle variabili considerate. RISULTATI. L’analisi fattoriale mostra che le varianze dei fattori e delle interazioni sono significative per tutti i caratteri considerati. La significatività delle interazioni esclude i tests sugli effetti principali. Riguardo l’interazione “anno × areale di coltura” i risultati del 1999 sono sempre significativamente inferiori a quelli del 1998; comunque la Costiera Adriatica Nord-Centro risulta essere il miglior ambiente nei 2 anni. L’interazione “areale di coltura × genotipo”, per quanto riguarda il volume del granello, evidenzia che il Simeto è la migliore varietà in tutte le zone seguita dal Creso; Mongibello emerge specialmente in Sicilia dove è stato selezionato. Per il peso 1000 semi Simeto, Creso e Colosseo confermano il loro buoni risultati in tutte le aree. Per la produzione di semola la varietà San Carlo raggiunge i migliori valori. CONCLUSIONI. La miglior area di coltura risulta la Costiera Adriatica Nord-Centro seguita dagli Appennini. Le zone tipiche di coltura del grano duro (Puglia, Sicilia e Sardegna) a causa della variabilità climatica danno risultati discontinui tra gli anni. Considerando l’interazione “areale di coltura × genotipo”, Simeto appare la migliore varietà in tutti gli areali per il volume del seme e peso 1000 semi; mentre per la produzione di semola emerge San Carlo. Gli areali che risultano migliori per i caratteri considerati sono quelli che hanno condizioni climatiche più stabili negli anni. Parole chiave: frumento duro, areali agroclimatici, analisi d’immagine, forma del granello, resa in semola.