Effect of Planting Pattern and Different Nitrogen Levels on Nitrogen Use Efficiency, Yield and Yield Components of Tomato (Solanum lycopersicum L. var. Karoon)

Tomato (Solanum lycopersicum L.) is a warm season crop that originated in South America. Tomatoes have significant nutritional value. In recent years, they have become known as an important source of lycopene, which is a powerful antioxidant that acts as an anticarcinogen. They also provide vitamins and minerals and serve as an important source of nutrients in contemporary diets due to readily available fresh fruit and processed products, their popularity, and the sheer volume consumed. Among the various factors affecting plant growth, optimum planting pattern plays an important role in preventing plant competition and poor fruit formation. Tomatoes can be planted in one of many different arrangements that provide adequate space for plant growth. Optimum use of nitrogen is one of the most important agricultural management factors in achieving proper performance in arid areas. Nitrogen use efficiency is greatly influenced by nitrogen levels and has an inverse relationship with the amount of nitrogen applied. The aim of this study was to investigate the effect of planting pattern (single row and twin row) and nitrogen levels on yield, yield components and nitrogen use efficiency of tomato cv. Karoon under arid region.
 

Two experiments were carried out at Bondarooz and Saad Abad agricultural research stations in Bushehr Province during 2017-18 to determine the best planting pattern and nitrogen fertilizer application on yield and its components of tomato cv. Karoon. The design was conducted as split plot layout based on a randomized block design with three replications. The main plot included plant pattern treatments in two levels (single row and twin row) and subplot included nitrogen treatments in four levels (no fertilizer, 90, 180 and 270 kg.ha-1). The studied traits included total fresh fruit yield, marketable fruit yield, total and marketable fruit per plant, fruit weight, fruit shape index, fruit hardness, chlorophyll index, and nitrogen use efficiency. For statistical analysis, analysis of variance (ANOVA) and Duncan’s multiple range test (DMRT) were performed using SAS ver. 9.1 software.
 

The results showed that the effect of region, planting pattern and nitrogen levels on the traits of total and marketable was significant at 1% probability level. The interaction effects of planting pattern and nitrogen levels on total fruit yield, marketable fruit yield, total number of fruits, chlorophyll index and fruit hardness were significant. The highest and the lowest total and marketable yields were obtained from single row planting method and application of 180 kg net nitrogen per hectare (54.08 and 46.50 t.ha-1) and twin row planting with non-application of nitrogen fertilizer (26.10 and 21.72 t.ha-1), respectively. The maximum number of fruits was 36.57 from single row planting and 180 kg Nitrogen fertilizer and the lowest number was 16.15 from twin row planting and without nitrogen fertilizer application. One of the reasons for this superiority can be the lower plant space in single row planting rather than twin row planting. The results of combined analysis of variance showed that only place effect on single fruit weight was significant at 1% probability level. The treatments with the highest chlorophyll index also had higher yields. Generally at all levels of nitrogen applications and interaction between planting pattern and nitrogen levels, nitrogen use efficiency decreased with increasing nitrogen fertilizer application. It may be related to limitation in uptake and sink capacities resulting in a saturation response. In Saad abad, simple effects of planting pattern and nitrogen on fruit weight had a significant effect at 5% probability level.
 

Single row planting was superior to twin row planting on all traits except fruit hardness. Nitrogen in arid regions can be considered as one of the most important factors affecting the performance and efficiency of nitrogen use. Single row planting and 180 kg Nitrogen application compared to a twin row planting without nitrogen increased the yield by 107%.