h n l f l n nd r t n b t n E r p n br d Ch tn t
G n rl n , ll Cr dd , 2 Cr t n n nd l S l r n I t t t d C lt v z n Arb r d ll Un v r t d r n , tr G r , 0 26 r n nd, 2 I t t t d r tt tt r Ind tr l d ll Un v r t d r n , Or , 0 26 r n , I A Y
ABSTRACT. Developmental stages of the growth cycle European chestnut-growing areas. However, chestnut from bud-swelling in the spring, through burr and leaf- blight, Phytophthora root rot and modern nut growing drop in the autumn are described for hybrids of Castanea considerations have stimulated interest in cultivars and crenata and C. sativa. Most of the stages are presented in hybrids of the more resistant C. crenata Sieb. and Zucc. a photographic sequence that details the appearance of from Japan (5). The smaller tree size and more precocious dormant vegetative and mixed buds, bud break, leafing bearing habits of the Japanese cultivars and hybrids would out, staminate catkin development, catkin type (astami- allow for more intensive orchard management and higher nate, brachystaminate, mesostaminate, logistaminate) (some early returns. examples from C. sativa), androgynous catkin develop- The present work shows some aspects of the phenol- ment, pistillate flower development, full bloom, fruit set, ogy, morphology and floral biology of Euro-Japanese ripening, fruit drop, yellowing of the foliage and leaf fall. hybrid chestnut cultivars through photographs that docu- Emphasis has been placed on the floral sequence in order ment the various vegetative and reproductive stages from that future work on chestnut may refer more precisely to bud-break in the spring to fruit and leaf-drop in the fall. the particular developmental moment within the phen- ological phase "bloom." MA E IA S A ME O S Each salient phenological phase and particular detail is described and numbered and most of the phases are Apart from a few scattered orchards of Euro-Japanese documented in photographic sequence. All observations, hybrids planted within the last 20 yr, the Italian (and except where indicated, refer to Euro-Japanese hybrid European) chestnut industry is based entirely on cultivars chestnut (C. r n t x C. t v trees growing at Cumi- of Castanea saliva Mill. These varieties have proven them- ana, in the province of Torino, 530 m above sea level. All selves over centuries of selection throughout the different data are from the 1990 and 1991 growing seasons. r . r nt br n hl t th x d b d . r 2. t t v b d. r . d br . r 4. Gr n h n . Figure 5. v v d nt. r 6. d l dr p. r . Op n n f th l v . Figure 8. v ll d tr b t d t p l . r . App r n f th t n . r 0. C t n d r n rl d v l p nt. r . El n t n t n . r 2. Gl r l v bl . r . E n f th t n . r 4. ll nth . r . A t n t t n. r 6. n t n t t n. r . App r n f p t ll t nfl r n . r 8. E n f t l . r . El n t n f t l . r 20. t ll t fl r t f ll bl . r 2 . t ll t fl r, d t l. r 22. t ll t fl r, t n. r 2 . ll nth , ndr n t n f C. crenata. r 24. ll nth , ndr n t n f C. saliva. r 2 . End f p t ll t r pt v t . r 26. Andr n t n dr p. r 2 . Gr n b rr . r 28. Y ll n f b rr . r 29. Burrs opening. r 0. Burr open, nuts fallen. r . Fallen burr with nuts enclosed. r 32. Yellow leaf and mixed bud. ESU S 0. C t n d r n rl d v l p nt, l n th 0 . th t n t nd ndr n t n r b rn n t t v nd x d b d th l f x l . . r nt br n hl t th x d b d . h br n hl t . t l p rt n f br n hl t th l n t n t n . h v v t t v nd x d (v t t v fl r b d pr 2.Gl r l v bl l n th t n. h t n t nt n r r l l pr p rt n . h t ll fl r r n t d nt x ll r l r l f v n r fr th b d . h p l nd b p l x d fl r h. An v r f 40 l r l r d tr b t d b d n C. t v , nd th nt r d t nd b p l l n th x f th t n. C t n l n th v r fr b d n C. r n t , C. ll l. nd th r h br d r 0 40 rd n t th p nd lt v r. b rn n l t r r th f th t nd v r t th .E n f th t n . h nd v d l t n t l nd f l nfl r n . fl r p d f x p rt d p r nth nd 8 2 2. t t v b d. h b d l n l th pr r t n . h p ll n h r t r z d b v r p n nt d f th v t t v x . d r. r v l r ( , 8 h t d th f ll n d v n f t n t p rd n t th pr n r b n f t n nd th l n th f th nth r f l nt : Bud-break and leafing-out t n t br h t n t t n t nd, l n Ch tn t r n r ll l t t b n l f r th n th t n t . pr n . p nd n n th lt v r nd th r n h r t 4. ll nth . h bl n p r d v r r n, l f n t b n n t fr th nd f rd n t th p , th lt v r nd th l t M r h t th nd f Apr l. h t fr l f n t t nd t n . ll nth n d r d t b th nt fr t t r t n n r ll b t n 40 nd 8 d . t h h t l t 0% f th t n h v p n fl r . . d br . h b d b t r d, n th n ll n b pr d d f r r th n nth d t th th p n f f d th br n f th b d l . l d nth r d h n . C t n dr p (ph t n t h n , 4. Op n n f th b d l th br n hl t. Gr n pr r v dr n nd f ll n f th t n rr p nd h n . t d n h n p ll n pr d t n. . v v d nt. h n l v b d t n h d. Catkin type 6. d l dr p. h n l v b n t nf rl nd th b d l f ll . .A t n t t n. h fl r th t t n . Op n n f th l v . h d f n t h p f th r rph l ll t r l n p ll n pr d d. h l v b n t h . ntr l p rt n f th fl r p d b l f l nt . 8. v ll d tr b t d l n th n h t. h h It l n lt v r n n M rr n r n r ll l v r th l n r t p l th t l f ll. h h r t r z d h v n t n t t n . l f h p n r ll ll pt l n l t , th r nd r h t n t t n (n t h n . h t n r n t b , r n t rr t t r l d nt t r fr l n nd d n t xt nd b nd th p r nth. n nd th n n t t p. h v r l f l n th h nth r pp r n r l t p ll n n v r 2 20 nd dth . h v n r v r v d nt. r . h l v f C. t v h v l th r t xt r , r d r M t n t t n (n t h n . h t n r r n b v nd l ht r r n b l . C. r n t h ll fr 4 l n nd xt nd b r l b nd th r n r l v th rr t , l d nt t r n . C. ll f th p r nth. ll n pr d t n l t d. l v r nt r d t n z nd t nt b l th 6. n t n t t n. h t n xt nd ll l p d t l nd l n dr b b th b v nd b l ( 0 . b nd th p r nth nd r fr l n . Ab nd nt p ll n pr d d. Staminate catkin development Andr n catkin development . App r n f th t n . h n x l t n t .App r n f th p t ll t nfl r n t th nfl r n ( t n b d t n h d fr th b f th r d t l t n . h f l fl r r ndr n nfl r n , h h r t n th p t l n t d n r p f ll thr n pr l nv l r . l t nfl r n t th b . h pp r n f th r t t f v ( t n f th nv l r t n t t n pr d th t f th ndr n t d v l p t r r l r th n ll b f rt l . n . h pr f fl r d ff r nt t n n th b d pl x, nv lv n n r n t l rph l l flowers d f t n nd r r n l n th d v l p nt l t ll t p r d. l r d ff r nt t n b n d r n th l t 8.E n f th t l . S v n t n n t l r h ld r r th ( . r n nd n (2 h v b th n h nd v d l x p rt d p t ll t fl r. rv d th t th f n l d v l p nt f th n l l nd .El n t n f th t l . h t l ll v nt ll f l fl r r d r n th f r t p rt f th v t r h l n th f 4 t 6 . t v l f th rr nt r r th. 20. t ll t fl r t f ll bl . h t l r r d d, l ndr l, ll t th b nd l br t th tip. Their color may vary fr r n h h t t very l ht ISCUSSIO yellow. The stigmatic surface is l t d t th very t p (11). h n Castanea is r b d t th rd r Fagales 21.Pistillate fl r, d t l. It is th p n nv l r th t nd t th f l Fagaceae (C p l f r ( . It includes develops into th b rr. 7-13 p ( , 2 n t v t th t p r t zones 22.Pistillate fl r, t n. Each f l fl r n f A , A M n r, M d t rr n n E r p nd th east- tains 6-9 ovules nd n nf r r 6-9 ll d ovary. Each rn p rt n f rth A r . h p f j r flower will give r t n h tn t th t , h v r, p rt n r C. mollissima (Ch n h tn t , C. t v contain one or r br . (E r p n h tn t nd C. crenata ( p n h tn t . A n pl nt, th h tn t h n nn l vegeta- ll bl t v nd r pr d t v l th t nv lv nt r rest Full anthesis n ndr n t n . h ntr l of th p r d, fr v b r t Apr l n n rth t p r t cli- three flowers n h p t ll t nfl r n ll r h t , nd p r d f nt n l t v v t t n d r n peak receptivity f r r f v d b f r th l t r l fl r h h h t , l v , fl r l r n nd fr t r nd (14). Full bl is n d r d t b h n styles f ll f d v l p. It l n ( , 2, 3, 4, 6, nd r n h th r (3, the three flowers r pl t l v bl . h v pr p d r ph r pr nt t n f th devel- 23. C. r n t . h ndr n t n f th p p nt l t . v r, f r th p rt l r tr nese and E r p n lt v r ll b t n t t r f th fl r r n rn d, nd th d ff r n or longistaminate. n th d ff r nt p , th r pp r t b l of 24.C. t v . h ndr n t n f th E r p n p f r f r n . cultivars will be t n t r br h t n t . A r t d r pt n f th ph n l l ph 25.End of p t ll t r pt v t . t ll t bl may f l t t l t n f r p t bl p ll n z r varieties last from three to f r , ft r h h th t l b n nd b f l t h tn t br d r . h pr nt r to brown and th v l , f f rt l z d, begin t r . h ld ll h tn t r r h r t t nd rd z th r 26.Androgynous t n dr p. h t n t p rt n f ld b rv t n fr r t r nd fr l t n to of the androgynous t n ll dr t th nd f p t ll t l t n. It h p d th t th r ll ntr b t t th receptivity yet r n nt t thr h t th d v l p n l d f th nt l f th b d nd fl r of th nt of th b rr . h tn t b l r f n th d ff r nt t f d v l p nt nd th t t h v pr t l ppl t n as ll. Fruit set 27.Growing b rr . h f nd t d p t ll t nfl r I E A U E CI E cences begin d t l d v l p n nt p n b rr . . r n , A. . O rv z n ll rf l f r l d l n The burrs grow t d l fr l thr h S pt b r lt v r d t n . v. Ort fl r fr t. It l n : 0 0 . 2. r n , A. nd n , A. . C ntr b t ll t d d ll October h n th r h th r x size. d ff r nz z n f r d l t n (C t n l v . . v. Or t fl r fr t. It l n :484 4 . p n n and nut drop . r n x, ., rlh , C., r h, . nd Ch p , . 8. 28.Yellowing f th b rr . Wh n th h tn t h v Ch t n r r d t n t C lt r . I U EC (M l rt r , r n . 2 pp. reached t r t th b rr b n t t rn l r fr r n 4. n , G. nd Ott n , M. 84. l v f n l 4 lt v r d to yellowish br n. h r p n n process f ll n t n pp n d br d r pp n n nt . of several d ff r nt p b l t th b rr p n, pl t 6 84 n: C r Int rn n l br l C t ñ , r z n ting at maturity nt t t f r v lv (29), dr pp n th O t br 84. pt. Inv t. r t. d r z n, nt v dr , Sp n. 42 pp. nuts to the r nd h l r n n n the tr (30), r . n , G. nd l tt , . 82. C t n lt r d fr tt : t the burrs may f ll r r l nt t th th n t en- z n p b l t d r l n . r tt lt r 44: 24. closed (31). Each f th t d h consequences 6. r v l r , . . r ll b l f r l d fr tt f z n on the b nt h rv t nd h ndl n f th h tn t . d ll C t n t v C t n r n t n l t rr t r d ll br . bbl z n n. , C ntr d St d l C t n (C. . . . Nut drop n th b rr (pr t t d b th involucre) may r S nt f ( ppl. 2 : 4 . facilitate h n l h rv t nd h lp pr v nt damage t . r v l r , . . r h ll d n z n ll r the nuts. If, n t d, th b rr r t r n n th tr , n z n d l p ll n n l t n . bbl z n n. 2, pp. d l one of the major b rd n f h nd h rv t ld b l C ntr d t d l C t n , (C. . . . r S nt f 2 : 2 . nated. 8. r v l r , . . Ind n d rv z n ll l r v r t t l n d t n . (C t n l v , M ll. . ( r ntr b t . Yellowing of the foliage and leaf fall bbl z n n. 2, C ntr St d l C t n (C. . . . r 32. Yellowing nd b n f th leaves nd x d S nt f ( ppl. 2 :2 66. . C , A. 2 . hát n r . M n r ph d nr C bud. The h tn t tr b n its vegetative r t p r d t n t C t n p . En l p d n d lv lt r , t. sometime b t n th end of O t b r nd the ddl of III. h v l r, r , r n . 600 pp. November. 0. Gr v , A. . 6 . K t h tn t p . Ann. p. rth. t Gr r A . 2: 8 0. . rr n, .E. . t r n n th l t n f th r pt v t t rf n C t n d nt t r h. . A . Ch tn t n d t n 6: 0 0 . 2. hn n, G. . 8 . Ch n p n : x n , d tr b t n, l Eff t f th p ll n t n t n th n b r f n t n th b rr. nd p rt n . Ann. p. rth. t Gr r A . 8: 8 62. ( p n th En l h r . p n. . r d. 2 : 80. . n , . . nd n ld ll , E. . Al n p tt d ll b l . S l n t, G. nd Ch p , . . b l r t d Ch t n r . f r l d l t n . r tt lt r :2 0. In t t t t n l d l r t n p r l r t , t 4. Sh r , I., Y n , M. nd Ot , C. . St d n th br d Ch p n n , I U EC ( r , r n . n b h v r f v r l h r t r n h tn t , C t n pp. II.