Testing Value for Cultivation and Use of Negin Pinto Bean (Phaseolus vulgaris L.) Cultivar Applying for Commercialization

IntroductionIntroducing improved bean cultivars with desirable characteristics such as high yield, large and marketable seeds, tolerant to environmental stress, erect growth type and suitable for mechanized harvesting are most important improvement goals in releasing new bean (Phaseolus vulgaris L.) cultivars. These characteristics are considered in the manual for the implementation of the bean agronomic value test (VCU). The aim of current research is to evaluate the agricultural value, yield and other important agricultural characteristics of a pinto bean cultivar (Negin) applying for commercialization in the most important bean growing climates in Iran. Materials and MethodsIn this experiment, candidate pinto been cultivar (Negin) along with 4 control cultivars (Sembol, Sepehr, Saleh and Kusha) were studied in 3 locations (Khomein, Ardabil and Esfahan) based on complete randomized block design experiment in 4 replications during two crop seasons (2021-2022 and 2022-2023). Characteristics listed in the "Manual for the implementation of the bean agronomic value test" include the number of days until flowering, the number of days until physiological maturity, plant height, first pod height, pods number per plant, seeds number per pod, pod shedding, the weight of 100 seeds, the yield of seeds fresh weight and water absorption capacity were recorded. Results and DiscussionResults showed that flowering occurred significantly earlier in Negin candidate cultivar (42.3 days) than control cultivars. Early flowering is considered as an important factor influencing yield of bean cultivars. This feature makes the flowering process start earlier before the onset of environmental stresses such as drought and high temperature. Also, in early flowering cultivars, the seed filling period will be longer. Seed ripening in Negin candidate cultivar occurred 5 days earlier than determinate control cultivars (mean ripening period 82.1 days) and 12 days earlier than indeterminate control cultivars (mean ripening period 89.5 days). Early ripening is not only an escape mechanism from end-season stresses such as drought, but it is also important because enables the early production and bringing to the appropriate market price, and for this reason many bean breeding programs in the world are focused on introducing of early cultivars. Among the studied cultivars, the number of seeds per pod in Kusha cultivar was significantly higher than the other studied cultivars, while this trait in Saleh, Sepehr and Negin cultivars was less than Kusha cultivar. In all 3 study locations, Sembol determinate cultivar had the highest hundred seed weight (52.9 g) and after that the other determinate cultivars (Negin and sepehr) had the highest hundred seed weight (48.9 g and 46.53 g respectively). Seed yield of determinate candidate cultivar (4235.8 kg.ha-1) was significantly more than other determinate Sepehr and Sembol cultivars (4027.1 kg.ha-1 and 34463.8 kg.ha-1 respectively) and seed yield of Negin cultivar had not significant difference with seed yield of indeterminate Saleh cultivar. In terms of performance, the Negin cultivar outperformed other determinate cultivars and matched the performance level of one indeterminate cultivar. Among the studied cultivars, Sembol showed the highest water absorption capacity, followed by Kusha, Saleh, Sepehr, and Negin. Thus, the Negin candidate cultivar exhibited the lowest water absorption capacity. ConclusionThe Negin candidate cultivar has strong potential as a new germplasm for national bean production due to its erect growth habit and ease of mechanical harvesting, early flowering and maturity, reduced water requirement (one to two times less), good marketability, and ability to produce larger seeds. AcknowledgementThis article is extracted from the research project of the Seed and Plant Certification and Registration Institute under the approved number 04-08-08-040-011096 dated 2024/06/15, which is hereby thanked and appreciated.