Effect of Varying Lopping Schedules and Stump Heights on Growth, Fodder Yield and Quality of Dual-purpose Barley (Hordeum distichon L.) 

Barley, the fourth most important cereal crop globally, is cultivated for its grains and green fodder. It’s grown on over 50 million hectares of land globally, producing 150.9 million metric tonnes per hectare. India produced about 1.91 million metric tonnes of barley on an average of 27.3 quintals per hectare in 2023, over 617.5 thousand hectares, while Punjab produced around 21,100 tonnes over 5,500 hectares, resulting in a yield of 3.84 tonnes per hectare (DES, 2023; USDA, 2023).
       
In modern agriculture, dual-purpose barley has become popular as a versatile crop that offers both fodder and grains in adverse climatic conditions and possesses a good regeneration capacity. In the arid and semi-arid areas of India, small and marginal farmers use barley to address the scarcity of green fodder during the lean winter period without compromising grain production (Manju et al., 2019). Lopping before the jointing stage for fodder production and optimal stump height influences regeneration, root systems, nutrient allocation and photosynthesis, all of which affect the plant’s regeneration. Early lopping of barley resulted in higher-quality fodder than later lopping (Prasanna et al., 2024). Additionally, delaying sowing negatively affected both fodder quality and grain production (Singh et al., 2017).
       
Fodder quality is mainly assessed by its digestibility, with major quality parameters being crude protein (protein), which is generally required for tissue growth and milk production and crude fibre (fibre), which supports the effective digestion system and nutrient absorption. An adequate amount of ash content in fodder results in better bone health and metabolic processes. Lower amounts of ADF (indigestible fibre) in fodder allow the animals to extract more nutrients and energy, which results in boosting their productivity. Moderate levels of NDF (total fibre) maintain proper rumen function and prevent digestive disorders in animals (Van Soest et al., 1991). 
       
In most parts of Punjab, the dairy sector holds equal significance as crop production, but due to a significant imbalance between the availability and demand of feed, especially during winters, it is adversely affected (Dhillon and Ram, 2021). The availability of green fodder in the Punjab region is only 28.4kg/animal, falling short of the required 40.0 kg /animal (Dhillon et al., 2018).
       
As many farmers in Punjab already grow barley for their grain, quality green fodder supply for their livestock can also be managed from the same without any need to grow a separate fodder crop. Thus, to mitigate the fodder shortage during the lean period in winter from the existing cropping pattern, this investigation was carried out to evaluate the effect of various lopping schedules and stump height on dual-purpose barley.

A field experiment was carried out at Lovely Professional University in Phagwara, Punjab, during the rabi seasons of 2022-23 and 2023-24. The site is at an elevation of 254 m. The temperature ranged from 33.1^°C to 7.1^°C in 2022-23 and 33.8^°C to 6.2^°C in 2023-24, with rainfall totals of 116.6 mm and 142.2 mm. The soil was sandy loam and its chemical properties were assessed before the experiment shown in Table 1.


 
Preliminary information
 
The experiment was organised in a randomised block design with ten treatments and four replications. The treatments include- T₁: No lopping (Control), T₂: Lopping @ 30 DAS + 1-inch stump height, T₃: Lopping @ 30 DAS + 2 inches stump height, T₄: Lopping @ 30 DAS + 3 inches stump height, T₅: Lopping @ 45 DAS + 1-inch stump height, T₆: Lopping @45 DAS + 2 inches stump height, T₇: Lopping @ 45 DAS + 3 inches stump height, T₈: Lopping @ 60 DAS + 1 -inch stump height, T₉: Lopping @ 60 DAS + 2 inches stump height, T₁₀: Lopping @ 60 DAS + 3 inches stump height.
       
DWRUB-52 was sown at 100 kg ha^-1 on November 19, 2022 and November 18, 2023, using a single-row hand drill at a 5 cm depth and 22.5 cm row spacing. A total of 75:30:20 NPK kg ha^-1 was applied, with nitrogen in three splits. The crop was irrigated three times: once before sowing and twice during critical stages. Broadleaf weeds were controlled with 2,4-D herbicide and one manual weeding.
 
Biometric observations
 
Five plants per plot were measured for height at 30, 60, 90, 120 days and maturity. Whole plant samples from borders were collected for dry matter assessment, using (Radford’s, 1967) formulas for growth parameters.

The equations used for the computations are as follows:

 

 

Whereas,
W1 and W2 = weights of dry matter (g) at times t1 and t2.
S = area and InW1 and InW2 are their natural logs.
 
Green fodder yield and quality
 
Green fodder lopping was done manually in the net plot area, excluding T₁-No cutting. The other treatments were lopped as specified and allowed to regenerate. Green fodder was measured per hectare and stump regrowth was monitored. Plant samples were collected, dried at 60^°C, ground and analysed for quality using standard procedures in Table 2.


 
Statistical analysis
 
Statistical analysis was performed using microsoft excel with ANOVA based on a randomised block design. Nine treatments were assessed for green fodder yield, regeneration days and quality, excluding treatment T₁ due to no lopping. The least significant difference (LSD) and standard error of the mean (SEM) were calculated at the 5% significance level.

Growth parameters
 
Data presented in Table 3 showing the periodical plant height (cm) of dual-purpose barley revealed that till 30 DAS, there was no significant influence on plant height since no treatment was given till that time. At 60 DAS, T₈ (51.6) showed a significantly higher plant height, which was statistically at par with T₁(51.4 cm) and T9 (50.6). In later stages, i.e. 90, 120 days and at harvest, T₁(86.1, 102.9 and 104.1) showed maximum plant height, followed by T₄(82.8, 99.0 and 99.6). Treatment shows significant results later due to lopping time, stump height and an extra 15-30 days for vegetative growth in plants at 45 and 60 DAS. These results are supported by Lal and Saini, 2016; Dudi et al., 2019; Neelam et al., 2022.


       
Throughout the entire experiment in both years, dry matter accumulation (g/mrl) was recorded as maximum in T₁(193.2), followed by T₄, except during 60 DAS due to lopping. The early growth stage shows non-significant data in dry matter accumulation (DMA). At 60 DAS, significantly, the highest DMA was recorded in T₁(193.2), which is statistically at par with T₈(192.2), T₁₀ (188.9) and T₉(184.3). At 90, the significantly highest DMA was recorded in T₁(291.2), which is statistically at par with T₄ (280.4). Significantly higher values are recorded at 120 and harvest is recorded in T₁(296.4, 301.2).
       
Data in Table 4 shows the growth between 0-30 DAS was non-significant in both AGR and CGR. Between 30-60 DAS interval, highest AGR and CGR was recorded in T₉ (2.05 g/plant/day, 8.20 g m^-1 row length day^-1) which is followed by T₁₀(1.99 g/plant/day, 7.99 g m^-1 row length day^-1), T₈ (1.95 g/plant/day, 7.83 g m^-1 row length day^-1) and T₁(1.92 g/plant/day, 7.71 g m^-1 row length day^-1). Growth rate between 60-90 and 90-120 DAS shows significantly higher growth in both AGR and CGR in T₁ (1.93 g/plant/day, 3.96 and 7.42 g m^-1 row length day^-1, 16.81 g m^-1 row length day^-1). Growth between 120- harvest shows a significantly higher growth rate in T₄ (0.83 g/plant/day, 3.35 g m^-1 row length day^-1), which is followed by T₁(0.82,3.29 g m^-1 row length day^-1).


       
Relative growth rate shows non-significant results between 0-30 and 60-90 DAS (Table 4). However, between 30-60 DAS, the significantly highest growth was recorded at T₁₀ (0.016 g g^-1 day^-1), followed by T₈ and T₉ (0.016 g g^-1 day^-1). In 90-120 DAS, T8 (0.0096 g g^-1 day^-1) shows the most comparable RGR, followed by T₉ and T₁₀ (0.0093 g g^-1 day^-1). From 120 DAS to harvest, T₁, T₃ and T₄ (0.0013 g g^-1 day^-1) show higher results.
       
Taller stumps preserve nutrients, provide energy for the new shoots and absorb sunlight, while growth hormones such as auxins and cytokines boost cell division and elongation (Meena et al., 2017; Nand et al., 2019).
 
Green fodder yield
 
Data presented in Table 5 revealed that significantly higher green fodder yield (t ha^-1) was recorded in T₈ (10.9), followed by T₉ (9.6), which stayed at par. Lopping at 60 DAS yields more fodder than at 45 and 30 DAS due to higher later vegetative biomass. Similar results are reported by (Dhillon et al., 2021). However, to get substantial fodder yield along with optimum grain yield in dual-purpose crops, it is important to decide on the right stage of harvesting (Singh et al., 2017). So, lopping done at 30 DAS with stump heights of 1-inch (2.9), 2-inch (2.7) and 3-inch (2.5) is better as cutting plants at an early stage gives them sufficient time for regeneration and further growth.


 
Days taken for regeneration
 
The regeneration after lopping in barley is illustrated in Fig 1. Among all treatments, T₂(10 days) led to shorter regeneration times. Early lopping focuses energy on root and shoot growth, improving regeneration without affecting grain yield. However, cutting the crop at 60 DAS occurred under poor temperature conditions, delaying barley regeneration. The findings are further supported by Dhillon and Ram, 2021.


 
Quality parameters
 
For desirable fodder quality, it should have higher levels of crude protein (%) and crude fibre (%) along with lower levels of ash content (%), neutral detergent fibre (%) and acid detergent fibre (%). Pooled data in Table 6 revealed that the lopping done in T₄ (15.23) contained remarkably richer crude protein, which was statistically at par with T₃(15.10). It also resulted in significantly lower neutral detergent fibre (40.28) and acid detergent fibre (21.77), which is desirable for livestock. Significantly higher crude fibre content was recorded in T₈ (25.17). Significantly lower ash content in fodder was recorded under T₂ (7.9). Good quality green fodder can be obtained until the flowering stage and lopping after this stage will impact quality and regeneration capacity (Singh et al., 2017). Higher crude protein content results from enhanced photosynthetic activity, food allocation and metabolically active tissue, contributing to growth and energy generation (Balfany et al., 2023; Sarkar et al., 2020).


       
As the plants mature, they accumulate more structural carbohydrates for structural integrity and cell development and the feed concentration rises due to higher nutritional absorption (Lee, 2018; Hundal et al., 2014; Meena et al., 2016). Higher neutral detergent fibre and acid detergent fibre values are a result of structural carbohydrates like cellulose, hemicellulose and lignin accumulating in later stages; these components provide rigidity, nutrient redistribution and protection against environmental stress (Osho et al., 2013). Similar results were also reported by Ishrath et al., (2018).
 

The researchers appreciate the support and lab facilities from the Department of Agronomy at Lovely Professional University.

The authors declare that there is no conflict of interest.