Effect of Storage Period, and Seed Size on Growth, Yield and Quality of Corn Varieties Zea mays L.

Abstract

Two laboratory experiments were conducted in the laboratories of General Board of Seed Test and Certification and two other field experiments at the trail field of Field Crops Dept. in the College of Agriculture – University of Anbar (Alternative Site-Abu Ghraib) for two seasons, Autumn 2015 and Spring 2016 to know the effect of storage duration and seed size in seed viability and vigour, growth, yield and quality traits of maize cultivars. Bothe laboratory experiments were conducted according to C.R.D design with factorial arrangement, where storage duration represent the first factor (2012, 2013 and 2014) for the first experiment and seed size (6.7, 7.8 and 8.6 mm) for the second experiment with three replicates in both experiments, while the second factor represented by maize cultivars (Baghdad 3, Fajr 1, Sara and Almaha) in both experiments, which have been conducted according to Randomized Completely Block Design (R.C.B.D.) with split plot arrangement. Cultivars were occupied the main plot, whereas storage durations were occupied the sub plots in the first experiment and seed size in the second experiment with three replicates for both experiments. The results of statistical analysis were as follows: Results showed the existence of significant effect of storage durations in most of studied laboratory traits except plumule length of seedlings in the laboratory standard germination test. The values of all traits were decreased as storage durations increased, therefore seeds which were stored for one year gave the highest percent of standard germination test (69%), radical length (15.11 cm), fresh and dry weight and normal seedlings percentage in cold and accelerated aging tests (33.66 and 60.75, respectively). Results showed that there is a significant effect of cultivars in most of studied laboratory traits, except plumule length, fresh weight of seedlings resulted from standard germination test. Sarah cv. seeds gave the highest percentage of standard germination test and Fajr 1 and Almaha cv. seeds gave the highest mean of radical length, while Almaha cv. seeds gave the highest mean of seedlings dry weight and normal seedlings percent in cold and accelerated aging tests without differed significantly against Sarah cv. seeds. Storage durations in the field experiment had significant effect in most of the studied traits in both ب growing seasons Autumn and Spring except ears number in the Autumn season which also showed decreasing in growth parameters, yield and seed quality as storage duration increased. So, stored seeds for the lowest duration (one year) gave the highest mean of filed emergence percentage and speed, and least days number for anthesis and silking, highest mean of plant height, leaf area, leaf area index, dry weight, kernel number per plant (482.8 and 584.7), 300 kernel weight (91.0 and 84.90 g), total grain yield (12.42 and 13.39 t h -1 ) protein and oil percentage for both seasons, respectively. Cultivars had significant effect in most of studied traits except for total dry weight, ears number and protein percentage in both growing seasons. Almaha cv. was significantly superior in field emergence percentage and speed, least days for anthesis and silking, highest mean of plant height, leaf area, leaf area index, kernel number per plant (533.5 and 606.6), 300 kernel weight and total grain yield (13.52 and 13.37 t h -1 ) oil percentage for both seasons, respectively. Results of statistical analysis of seed size experiment revealed significant effect of seed size grading in all studied laboratory traits, as traits mean increased by sowed seed size. The higher seed size gave the highest mean of standard germination test (70.9%) radical and plumule lenght (17.41 and 14.12 cm, respectively) fresh and dry weight and normal seedlings percentage in cold and accelerated aging tests. Cultivars also showed significant difference in the laboratory traits, as Sarah cv. seeds gave the highest mean of standard germination test and normal seedlings percentage in cold and accelerated aging tests. While Almaha cv. seeds gave the highest mean of radical length and fresh and dry weights. In the field experiment, the effect of seed size grading into three different sizes was extended to field emergence, growth, yield and quality traits in both growing seasons. The larger seed size were superior and gave the highest mean of field emergence in the Spring season, field emergence speed in both seasons and the least days number for anthesis and silking, highest mean of plant height, leaf area, leaf area index, plant dry weight, ears number, kernel number per plant, 300 kernel weight, total grain yield protein and oil percentage for both seasons. ج Cultivars differed significantly in most of studied traits in both growing seasons, as Sarah cv. plants were significantly superior and gave the highest mean of field emergence percentage in both growing seasons and filed emergence speed in the Autumn season. Almaha cv. gave the highest mean of filed emergence speed in the Spring season and the lowest mean of days for anthesis in both seasons and the lowest mean of days for silking in Spring season and for leaf area and leaf area index in both seasons, kernel number per plant in Autumn season, 300 kernal weight and grain yield in both seasons, and oil percentage in spring season. Baghdad 3 cv. plants gave the highest mean of plant height, dry weight in both growing seasons. Accordingly, we recommend not to prolong the duration of storage for more than one year, especially in the open storage. Also, we recommend to grade seeds and select those with larger size for planting or to improve the emergence of cultivars seed with low viability, and planting Almaha cv. seeds because it’s the best in filed emergence, growth, grain yield and quality traits.