Screening of Tomato Genotypes for Various Yield and Quality Parameters under Regulated Deficit Irrigations in Northern Dry Zone of Karnataka

Abstract

as influenced by irrigation levels Sl. No. Genotypes Number of fruits / plant Average fruit weight Equatorial diameter (mm) Polar diameter (mm) IW/CPE ratio Control 1.2 0.4 Mean Control 1.2 0.4 Mean Control 1.2 0.4 Mean Control 1.2 0.4 Mean 1

Estimates of Genetic Variability, Association Studies and Per se Performance of Tomato Genotypes for Growth and Yield Parameters Under Drought Stress Conditions

“…The mean number of fruits per plant (20.53) average fruit weight (28.57 gm) and fruit yield per plant (0.73 kg) were considerably reduced when compared to well-irrigated conditions (31.64 fruits, 42.84 gm, and 1.36 kg, respectively) with a percent reduction of 35.11%, 33.31%, and 46.32%, respectively under drought stress. This decreasing trend for fruits per plant, average fruit weight and yield per plant was also reported by Sivakumar et al [17] Prakash et al [15] and Parveen et al [16]. The reduction in fruit yield parameters under drought stress conditions is due to reduced water content in plants that adversely affects plant growth leading to reduced plant height and number of leaves [17], reduced photosynthetic efficiency, increased flower abscission, reduced pollen fertility [20] resulting in lower yields.…”

“…The number of fruits per plant demonstrated moderate heritability (56%) and high GAM (20.16%) under drought stress conditions whereas high broad sense heritability and GAM under control conditions. However, under control conditions, low to moderate estimates of GCV (<20%) coupled with high broad sense heritability (˃ 60%) and moderate GAM (10-20%) were noticed for plant height, stem girth and number of primary branches and days to flowering [15,24]. This indicated moderate variability in the studied accessions, but highly heritable variation owing to the additive gene action for these traits.…”

“…The results of evaluation of 39 genotypes of tomato indicated a large variability in response to water stress, as revealed through analysis of variance showing highly significant differences among the genotypes as well as the interaction effect between the genotypes and irrigation levels for all the traits studied (Table 2). The per se performance of 39 tomato accessions revealed a decreasing tendency for plant height, stem girth and number of primary branches under drought stress as compared to irrigated conditions [14,15,16]. Average plant height was highest under control condition (78.42 cm) as compared to drought stress condition (46.66 cm).…”

“…The reduction in fruit yield parameters under drought stress conditions is due to reduced water content in plants that adversely affects plant growth leading to reduced plant height and number of leaves [17], reduced photosynthetic efficiency, increased flower abscission, reduced pollen fertility [20] resulting in lower yields. Also, to maintain relative water content under drought and to avoid water loss through transpiration, the plant closes its stomata; it disrupts leaf gas exchange properties which limit the source size and activity (Photosynthesis) and partitioning of photo assimilates to fruits (sink size and activity) [15].…”