Influence of boron in organic red clover (Trifolium pratense L.) seed production

Abstract

The effect of boron (B) on flower development, nectar production, seed yield and germination in organic red clover was investigated in soils with <1 mg B kg−1. Different techniques for application of a liquid B product were studied in four field experiments in 2009–2011. The treatments were as follows: control (no B); three rates of B application to the soil at sowing; and three rates of B as foliar application in the harvest year. The effects of B application varied between the fields and included increased seed yield, seed weight of fifty inflorescences (IFs), number of florets IF−1 and nectar volume IF−1. The greatest effects on seed yield were found in treatments with low B rates. Boron application increased seed B concentration in only one experiment and had no effect on shoot B concentration. The percentage of seeds with normal germination increased with increasing seed B concentration (R2 = 0·73). Seed weight of fifty IFs and number of IFs m−2 increased with increasing shoot B concentration. Boron is therefore an important element for red clover seed production. Further knowledge on improving the B uptake of red clover plants is required to improve seed yield and quality.

Influence of boron on seed yield and seed quality of organic white clover (Trifolium repens L.)

“…Boron application had little effect on the B concentration in the shoots and roots at budding stage and in the seed, compared with the control, although soil B concentration increased (Table ). Similar results were also found in red clover (Stoltz and Wallenhammar, ), although in other crops (lentil, chickpea and wheat) increased B concentrations in the seed have been obtained as a result of B application to the soil (Johnson et al ., ). The absence of any increase in B concentration of the plants in the present investigation might explain the absence of yield increase.…”

“…The seeds from Experiment 1, with a relatively lower B concentration (average of 17 mg kg −1 ), had a lower percentage of seedlings with normal germination and a higher percentage of hard seeds compared with Experiment 2, in which the seed B concentration was on average 22 mg kg −1 (Table ). Improved germination in seeds with a higher B concentration has also been reported for red clover (Stoltz and Wallenhammar, ), soybean ( Glycine max L.) (Rerkasem et al ., ) and pea (Bonilla et al ., ). In dill ( Anethum graveolens L.), seed germination increased after priming with B up to a certain concentration (38·93 mg kg −1 ); thereafter, the germination decreased (Mirshekari, ).…”

“…Although in Experiment 1, the results indicate an apparent tendency (10% increase) for increased seed yield following soil application of B, and for higher seed weight in 50 inflorescences in soil B treatments compared with control, the differences did not reach significance (Table ). An advantage of soil application of B, compared with foliar application, was previously found for red clover ( Trifolium pratense ) seed production (Stoltz and Wallenhammar, ).…”

Response of Pulse and Oilseed Crops to Boron Application: A Review

“…They observed that application of boron at the rate of 5 kg B ha -1 had significant effect on plant height, number of branches plant -1 , number of pods plant -1 , number of seeds pod -1 , 1000-seed weight and seed yield of mung bean seed. Stoltz and Wallenhammar (2013) studied the effect of soil and foliar applied boron (B) on flower development, nectar production, seed yield and germination in organic red clover was investigated in B deficient soils. The results showed that there is a greater increase in seed yield when B is applied to the soil compared with foliar application.…”

Influence of seed treatment with mineral nutrient products on emergence and growth in spring oilseed rape (Brassica napus L.)

“…It is confirmed that the concentration of mineral nutrients in the seed influences germination and early growth, e.g. manganese and zinc in wheat, phosphorus in narrow-leafed lupin, phosphorus and molybdenum in common bean and boron in red clover seed (Marcar and Graham 1986, Rengel and Grayham 1995, Thomson et al 2008, Sanches Pacheco et al 2012, Stoltz and Wallenhammar 2014. Previous investigations showed enhanced germination and growth in a number of other crops e.g.…”