Growth and gas changes of melon seedlings submitted to water salinity

Abstract

The melon is an outstanding fruit crop in Brazil, mainly in the Northeast region due to favorable conditions for cultivation. Water salinity affects the growth and production of several species, but there is tolerance among cultivars of the same species. The objective of this study was to evaluate the growth and gas exchange in melon seedlings subjected to water salinity. Experiment was carried out in a greenhouse belonging to the Center of Sciences and Agri-Food Technology, Federal University of Campina Grande, Pombal, PB, Brazil, from September to October 2016. The experimental design was a randomized complete block design in a 6 x 5 factorial scheme, with four replicates, for six cultivars of melon (Natal, Solares, Goldex, Iracema, Mandacaru and Amarelo Ouro) and five irrigation water salinity levels with the following electrical conductivities: 0.3, 1.1, 1.9, 2.7 and 3.5 dS m-1. Each experimental unit consisted of a polypropylene container with a volume capacity of 0.350 dm3, which contained soil + Basaplant® commercial substrate at a ratio of 2:1. At 25 days after sowing, the plants were evaluated for growth, gas exchange and dry mass accumulation. Increased salinity of irrigation water inhibits the growth, dry mass accumulation and physiological processes of melon cultivars. The cultivar Natal showed to be more tolerant, while the cultivars Solares, Goldex, Iracema and Mandacaru were moderately sensitive and the cultivar Amarelo Ouro was more sensitive to the salinity of irrigation water.

Cytokinin and Auxin Influence on Growth and Quality of Watermelon Irrigated With Saline Water

“…As for the isolated applications of the regulators (0/100% and 100/0% CPPU/IAA, respectively), it was observed that CPPU promoted higher yields for plants under high EC compared to IAA. One of the signs of stress caused by the excess of salts is the rapid and intense reduction in the growth rate, mainly in leaf area, a response caused by the change in physiological parameters (SOUSA et al, 2019). For TDM, a similar behavior was found between the treatments 25/75, 50/50 and 75/25% when the plants were irrigated with normal water, while at a salinity level of 2.0 dS m -1 , they obtained greater accumulated mass (14.32 g) with the proportion 25/75% (Figure 1B).…”

Uso de Trichoderma spp e estresse salino na produção de mudas de melancia

“…) também foi constatada porSousa et al (2019) no crescimento inicial de meloeiro, ao estudar seis cultivares: Natal, Iracema, Goldex, Solares, Mandacaru e Amarelo Ouro, em que a cultivar Natal revelou-se a mais tolerante e Amarelo Ouro mais sensível à salinidade da água na fase inicial de crescimento.A inoculação com os Trichodermas spp. interferiu na tolerância das cultivares (Figura 3E) com mais expressividade nas cultivares Fair Fax e Crimson Sweet em que a aplicação com Trichoderma longibrachiatum proporcionou acúmulo de biomassa em torno de 72,3% e 75,5% contra 60,5 e 57,4% com Trichoderma harzianum, equivalente ao incremento de 16% e 24%, respectivamente, nessas cultivares.…”