The effect of washing leave of potato after irrigation with the fish farm effluent on chlorophyll fluorescence and some characteristics of potato

water scarcity is one of the primary problems in arid and semi-arid regions such as Iran. Many previous studies corroborated that using aquaculture wastewater might be a good alternative for supplying irrigation demand in the arid and semi-arid countries such as Iran. In fact, the effluent of the fish farms that contain a notable amount of phosphor and nitrogen are high nutrition for different plants. Depending on water quality, irrigation method and type of crop might change. The elements present in the fish effluent interact with each other and it is possible to increase or decrease the absorption of an element through the leaves to have a negative effect on the chlorophyll fluorescence. In an attempt to reduce foliar absorption, we used post-washing, pre-washing and pre and post washing. Therefore, the investigated factors include irrigation at two levels, A1 (irrigation with fresh water) and A2 (irrigation with fish farm effluent), as well as washing the leaves of the plant in four levels they are Before applying fish farm effluent to the leaves, they were washed for ten minutes with fresh water (B1), after applying fish farm effluent to the leaves, they were washed for ten minutes with fresh water (B2), The leaves were washed with fresh water for ten minutes both before and after applying the fish farm effluent to them (B3) and the leaves were not washed at all (B4). The main objective of the present study is to provide a solution to reduce the negative effects of fish effluent in sprinkler irrigation on chlorophyll fluorescence.

The present study was conducted on pots; the pot experiments were carried out at the research site of the University of Kurdistan. This research farm is located at the Dehgolan plain in Kurdistan province. As presented in the previous section we applied two types of water for irrigation in the treatments including fresh water from the available well in the experimental site and the fish farm effluent from the available fish farm as well as washing the leaves of the plant in different situations including Before applying fish farm effluent to the leaves, they were washed for ten minutes with fresh water (B1), after applying fish farm effluent to the leaves, they were washed for ten minutes with fresh water (B2), The leaves were washed with fresh water for ten minutes both before and after applying the fish farm effluent to them (B3) and the leaves were not washed at all (B4). In the present study soil moisture was measured in the daily scale before the irrigation then irrigation was carried out based on the efficiency of required soil moisture. The PMS-714 moisture meter was applied for measuring the soil moisture in the experimental site. At the end of the cultivation period, the yield of potato in each pot was collected and measured separately. Then the average of all the potato was applied in the further analyses. Data were analyzed with Rstudio, and mean values of the treatments were compared by the LSD test at a 5% and 1% significance level.

The results of this research showed that B3 compared to B4 increased yield by 10.13%, maximum fluorescence by 20.44%, variable fluorescence by 28.67%, maximum photochemical quantum yield of photosystem II by 6.66%, dry weight of stem 37.98%, dry weight of leaf by108.06% and dry weight of root 125%. previous studies corroborated that effect of leaf washing when unconventional water is used has a positive effect on the absorption of elements by the plant and growth indicators. Also, previous studies showed that the simultaneous use of fresh water and water unconventional methods reduce the toxic effects caused by the substances in the wastewater and improve the yield and physiological indicators of the plant. It has been reported that when leaves are washed with fresh water before and after salt water is applied to the leaves, the concentration of chlorine and sodium in the leaves is lower than when leaves are not washed at all. They stated that when the leaves are washed before applying salt water, the leaves are hydrated and the capacity to absorb elements by the leaf is reduced, and also when the leaves are washed after applying salt water, the elements and materials are washed on the leaf. And leaf absorption is reduced. Therefore, it increases yield. It is recommended to use the strategy of simultaneous use of fish waste and fresh water in sprinkler irrigation system to increase chlorophyll fluorescence and other characteristics of potato plant.