The Effect of Transplant Age and Plant Density on Yield and Yield Components of Chinese Lantern (Physalis alkekengi L.) as a Medicinal Plant

IntroductionNowadays, need for medicinal plants are increasing to the extent that it has become a very important in terms of trade. Chinese lantern belongs to Solanaceae family and it is indigenous to the American continent. There are many benefits to Chinese lantern such as anticancer activities against hepatitis and Diabetes. The optimum planting date of Chinese lantern is one the most important factors for a successful cultivation. Interactions between environmental and plant factors cause planting date, transplanting date and the age of the transplants vary from one location to another, even among different genotypes. Moreover, the optimum plant density is an essential factor to reach a high yield. In fact, low plant density leads sources to waste; on the other side, high plant density causes yield reduction due to intense competition. The present study aims to investigate the effects of different plant densities and age of transplants on yield and yield components of Chinese lantern in Mashhad, Iran.Materials and MethodsA field study in a factorial experiment based on a randomized complete block design was carried out with three replications at the research field of faculty of agriculture, Ferdowsi University of Mashhad, Iran in 2016. The experimental treatments were the combination of transplants age (5, 8 and 11 weeks) and four levels of the plant density (5, 6.7, 10 and 20 plants per square meter). All the transplants were transferred in the field on May 5. Plots were designed with 3 m long and 2 m width, 0.5 m apart from each other. The first irrigation was done three days before transplanting date; and further irrigation was done immediately after transplanting. At the maturity stage, five plants in each plot were selected randomly to measure plant height, fruit number, fruit weight per plant, single fruit weight, the number of seeds per fruit and 1000 seeds weight. Final fruit yield, biological yields and harvest index were measured by harvesting 1 m2 of the central part of each plot. All data were subjected to analysis of variance (ANOVA) using SAS 9.1 software (SAS, 2011). When F test indicated statistical significance at p<0.01 or p<0.05, the least significant difference (LSD) was used to separate the means.Results and DiscussionThe highest fruit weight per plant was acquired by the density of 5 plants per m2 and transplant age of 8 and 11 weeks. Increasing plant density from 5 to 20 per m2 led to decrease fruit weight in plant. In the low density, plants can access to the sufficient amount of recourses, so, yield rises; while in the high density, plant competition causes assimilation to reduce. The highest biological yield (16 tons per hectare) was obtained in the 8- and 11-week transplants, and density of 20 plants per m2. The highest fruit yield was achieved at 10 plants per m2 and 11-week-old transplant which was significantly different from the other treatments. The highest fruit yield was obtained by the density of 10 plants per m2 followed by 6.7 plants per m2 when 8-weeks transplant was used. The 11-week-old transplant and the density of 5 plants per m2 produced the highest fruit number (109). In general, with increasing age of transplants, the number of seeds per fruit increased. The results showed that increasing age of transplants from 5 to 11 weeks led to increase seeds weight from 2.14 g to 2.87 g. Plant height increased significantly by increasing plant density. The density of 5, 6.7 and 10 plants per m2, and 8 and 11 weeks old transplants had the highest harvest index. The lowest harvest index was seen at 20 plants per m2. Overall, 5-week-old transplants could not produce proper mature plants; also, the density of 20 plants per m2 was not favorite for most of the traits except for biological mass and plant height.ConclusionsThe results showed that plant density and the age of transplants had significant effects on the studied traits. All the traits were superior when 8- and 11-week old transplants were used. It seems that 5-week-old seedlings were not enough strong to grow well and did not have a normal plant size to provide successful mature plants in the field. Plant height and biological mass increased when plant density increased.