The compound growth rates (CGRs) of export of vegetable products from India was calculated by using the exponential function of the following specification: (1)Yt=abt

Where,

Y_t = Dependent variable (Export quantity/ export value); t = Time variable in years taking the value of 1, 2, 3,..., n; a = Intercept; b = Regression coefficient (1 + r).

For the purpose of estimation, the equation is expressed in logarithmic form. (2)log⁡Yt=log⁡a+tlog⁡b

The value of log b in equation (2) was computed using the formula, (3)log⁡b=(∑tlog⁡Y−(∑t∑log⁡Y/N))∑t2−(∑t2N)

Where,

N = Number of years.

Subsequently, the compound growth rate (%) was computed using the formula, (4) Compound growth rate (r)=[( Antilog of log⁡b)−1]∗100

Student ‘t’ test was used to determine the significance of the growth rates obtained for which, the following formula was employed, (5)t=log⁡b/SE(log⁡b) (6)log⁡(B)=∑(Y−Y¯2)2−log⁡b∗(∑(Y∗t)−∑(Y)∗t¯)(N−2)∑(t−t¯)2

The calculated ‘t’ values, from equation (6), was compared with the table ‘t’ values and the level of significance was tested for 1 and 5 per cent, probability levels.

In order to study variability in export trade of vegetable products, an index of instability index was used as a measure of variability. The coefficient of variation (CV) was calculated by using the following formula: (7)CV(%)=S/X¯∗100

The tendency factor was tested for its consequence. Whenever, the tendency factor was found to be noteworthy, the dissimilarity around the tendency rather than variation around mean was used as an index of instability. The formula suggested by Cuddy and Della (1978) was used to calculate the notch of dissimilarity around the tendency. (8)Ix=CV(1−R¯2)

Where, Ix is Instability Index, CV = Coefficient of variation, R² = Adjusted coefficient of multiple determination.

According to Das et al. (2016) for assessment of risk factor in growth rate there are range between (0 to >10) which are likely as; Low growth rate (0 to 5), Medium growth rate (>5 to 10) and High growth rate (>10).

According to Sihmar, (2014) for assessment of risk factor in instability analysis there are range between (0 to >30) which are likely as; Low instability (0 to 15), Medium instability (15 to 30) and High instability (>30).

It can be seen form Table 1 that the growth rates of quantity and value of vegetable products exported were positive and significant during both the periods as well as in the overall period, except in case of the export quantity of cucumber and tomato fresh or chilled during Period-II.

Further, it can be revealed that per unit export price of onion fresh or chilled, cucumber, tomato fresh as well as tomato ketchup increased significantly during Period-II. The rosy picture of these commodities should be taken into consideration by the exporters and policy makers. Similarly, probable reasons for significant decline in per unit price of onion dried/ sliced/broken/powder and potato other than seeds (fresh or chilled) during the entire period of study should be explored.

It can also be observed from the results that the compound growth rates of onion fresh or chilled export from India during Period-I were found positive and highly significant in case of quantity (15.72%) and value (17.88%), while it was negative (-1.31%) for export price. During PeriodII, export quantity (0.68%), export value (4.30%) and export price (3.59%) of onion fresh or chilled were positively significant at 1 per cent level of significance. The increase in growth of price in Period-II may be due to decrease in export quantity to meet risen domestic demand. During PeriodIII, the pattern of the compound growth rate was similar to the pattern as observed in Period-I. The compound growth rate of quantity (8.69) and value (15.02%) observed positive and highly significant. while, negative growth rate was observed in export price (-1.55%).

The annual compound growth rates of exports of onion dried/sliced/broken/powder reported positive and significant in case of both export quantity (24.54%) and export value (21.78%), but the rate of export price (-5.26%) showed a negative growth during Period-I. The similar pattern was observed during Period-II, where the positive growth rate in both export quantity (5.45%) and export value (11.38%) noticed significant. But the export price (-2.04%) showed a negative growth rate. During overall period, growth rate in export quantity (13.28%) found positive and significant, but in case of export value (19.21%), it was non- significant, whereas for export price, the growth rate (-2.10%) was negative.

The results of annual compound growth rates of export of potato other than seeds depicted a positive trend in both export quantity (19.11%) and export value (18.46%) and found significant at 10 per cent level of significance, whereas growth rate of export price (-3.65%) was negative during Period-I. During Period-II, it also registered positive growth rate in both export quantity (10.36%) and export value (18.09%) but the growth rate was negative in case of export price (-0.75%). During overall period also, it registered positive growth rate in both export quantity (17.41%) and export value (23.86%) whereas, negative growth rate was realized for export price (-1.87%). In all the periods, export quantity and export value had positive growth, but export price witnessed negative growth. Kavita et al. (2015) also observed similar trend in their study on mango export from India. The results of cucumber prepared or preserved reflects a positive and significant growth in both export quantity (26.12%) and export value (26.43%) whereas, negative growth rate for export price (-2.88%) were observed during Period-I. During Period-II, it registered negative growth rate in export quantity (-4.79%) whereas, the growth rate was positive and highly significant in both export value (4.92%) and export price (2.22%). The higher growth rate in both export volume and export value were noticed during Period-I and Overall period, but in Period-II, it declined significantly due to tough competition faced by Indian exporters in international market and also due to significant increase in domestic production of cucumber prepared or preserved. During the overall period, it also registered positive and significant growth rate in both export quantity (9.87%) and export value (16.36%). Whereas, export price(-1.48%) registered a negativelysignificant growth rate.

The pattern of the compound growth rate of cucumber provisionally preserved was similar to the pattern of cucumber prepared or preserved as observed in all the periods. Similar growth pattern was observed during Period-I and Overall period, whereas negative growth rate was realized for export quantity during Period-II.

The results of annual compound growth rates of export of tomato fresh or chilled observed a positive and significant trend in export quantity (57.22%), export value (64.39%) and export price (1.29%) during Period-I. During Period-II, it registered a negative growth rate in export quantity (-5.69%), whereas, the growth rate was positive in both export value (1.90%) and export price (0.22%) and the export price was significant at 1 per cent level of significance. During Overall Period, it registered positive growth rate in both export quantity (30.68%) and export value (39.60%), whereas, export price (-0.61%) registered significantly declining rate.

Tomato Ketchup or sauce registered a positive growth rate in export quantity (8.22%), export value (13.18%) and export price (1.31%). Which were significant respectively at 10 and 1 per cent, level of significance during Period-I. During Period-II, positive and significant growth rate was observed in export quantity (2.47%), export value (10.81%) and export price (0.30%). But in Period-II, the growth rate was found decreased in export quantity (2.47%). This may be due to increase in demand in domestic area. During overall period, the positive growth rate was observed for export quantity (14.40%) and export value (20.32%) and export price was declined significantly at the rate of−2.16 per cent per annum. These results are in conformity with the findings obtained by Karthick et al. (2015) in their study on export of Ginger from India.

The results showed that all vegetable products exports, registered high instability except onion fresh or chilled (export quantity) during Period-I. The instability in vegetable products export quantity was higher in Period-II as compared to Period-I. In case of export price, the instability ranged from 13.06 to 30.15 during Period-I (Table 2).

During Period-II, the instability in export quantity, value and price, respectively ranged from the 13.78 to 66.09, 23.10 to 70.94 and 13.18 to 39.54. During overall period, the instability in vegetable products’ export ranged from 31.85 to 98.32, 29.19 to 103.23 and 14.71 to 43.08, respectively in case of quantity, value and price. Tomato fresh or chilled and tomato ketchup or sauce in both export quantity and export value showed high instability. Whereas tomato fresh or chilled and tomato ketchup or sauce are the most unstable commodity in terms of export quantity and export value. During Period I, the lowest instability in terms of export quantity was observed in onion fresh or chilled i.e. 27.84 per cent, whereas, 35.76 and 13.06 per cent in cucumber provisionally preserved in terms of export value and export price, respectively.

During Period-II, the lowest instability in terms of export quantity and export value were observed in cucumber prepared or preserved i.e. 13.78 and 23.10 per cent, respectively, whereas in case of export price the lowest instability was observed in cucumber provisionally preserved (13.18%). The result are in the line of Das et al. (2016) in their study on export of Marine products.

In case of overall period, the lowest instability in terms of export quantity was observed in onion fresh or chilled i.e. 32.67 per cent, whereas, the lowest instability in export value and export price were observed in cucumber prepared or preserved and cucumber provisionally preserved about 29.19 and 14.71 per cent, respectively (Table 2).

As furnished in Table 3, it can be observed that in case of export quantity onion fresh or chilled, cucumber prepared or preserved and cucumber provisionally preserved were found in medium growth and high instability. This implies that, none of the product were found in desirable situation of low instability and high growth. In case of export price the majority of the vegetable products were placed into high growth with high instability, which indicates that, none of the vegetable products in any countries were found to be placed in desirable situation during the study period. In case of vegetable products export price Onion fresh or chilled and tomato ketchup or sauce were placed in low growth with high instability, onion dried/ sliced/broken/powder, potato other than seeds (fresh or chilled), cucumber prepared or preserved and tomato fresh or chilled were placed in low growth with medium instability, while cucumber provisionally preserved was placed in low growth with low instability, the result indicates that none of the countries reported to have desirable situation of high growth with low instability in case of export price of vegetable products.