Phosphites and chitosan were evaluated in target spot control, nutrition and gas exchange in cucumbers. Three weekly sprayings of commercial products were conducted, and Corynespora cassiicola (causal agent of target spot) was inoculated in the second and third true leaves four days after the last spraying. Zn, Mn, K and Cu phosphites reduced the disease severity, but the treatments had no effect on the development of the plants and the accumulation of macronutrients in the above ground part, with the exception of sulfur. The accumulation of Cu, Mn and Zn micronutrients were higher in plants treated with Cu, Mn and Zn phosphites, respectively. The green color index was influenced by the treatments after pathogen inoculation, with the highest values for Zn and Cu phosphites. Before inoculation, the products influenced net CO₂ assimilation rate (A), stomatal conductance (g_s) and internal CO₂ concentration (C_i). The parameters g_s and C_i increased, which indicates that the treatments can physiologically benefit the plants in the absence of a stress condition. After fungal inoculation, the Cu, Mn and Zn phosphites caused positive physiological effects, leading to the highest A values and adequate carboxylation efficiency (CE), which increases the capacity of plants to assimilate CO₂. These phosphites also maintained adequate water use efficiency and g_s and C_i values. Such indexes corresponded to lower disease severity, indicating that Mn, Zn and Cu phosphites reduced the stress caused by the disease, preserving the functionality of the photosynthetic apparatus.

亚磷酸盐和壳聚糖在黄瓜靶斑控制、营养和气体交换方面进行了评估。进行了三周商业产品喷洒，Corynespora cassiicola最后一次喷药4天后，在第2、3片真叶上接种(靶斑病害剂)。Zn、Mn、K和Cu亚磷酸盐降低了病害的严重程度，但处理对植物的发育和地上部分常量营养素的积累没有影响，硫除外。分别用亚磷酸铜、锰和锌处理的植物中铜、锰和锌微量营养素的积累较高。绿色指数受病原体接种后处理的影响，其中亚磷酸锌和亚磷酸铜的值最高。接种前产物影响净CO ₂同化率( A )、气孔导度( g _s )和内部CO ₂浓度(Ç_我）。参数g _s和C _i增加，这表明处理可以在不存在胁迫条件的情况下在生理上有益于植物。真菌接种后，Cu、Mn 和 Zn 亚磷酸酯产生了积极的生理效应，导致最高的A 值和足够的羧化效率 (CE)，这增加了植物吸收 CO ₂的能力。这些亚磷酸盐还保持了足够的用水效率和g _s和C _i值。这些指标对应于较低的疾病严重程度，表明亚磷酸锰、锌和铜减少了疾病引起的压力，保持了光合装置的功能。